As a lens for current bifocal eyeglasses, a progressive lens is widely known. The progressive lens is also referred to as “no-line bifocal lens”, where a far-vision region for looking at something in the distance, a near-vision region for looking at something near (presbyopia part), and an intermediate region are disposed in one lens.
The intermediate region is a region in which, from diopter power (hereafter referred to as eyeglass degree) of the far-vision region to the eyeglass degree of the near-vision region, the eyeglass degree is progressively changed. For example, refractive power is changed by a method disclosed in Patent Document 1.    Patent Document 1: JP-A-09-159976
In these progressive lenses, the eyeglass degree changes in a non-step manner from the far to the near, thereby providing an advantage in that any distance can be focussed with one lens. Also, since there is no boundary in the outer appearance, a so-called sense of agedness is absent, so that it is excellent in fashion property.